Slide control, particularly for the adjustment of swinging bodies of axial piston pumps and/or motors



175,365 SWINGING March 30, 1965 E. ALLGAIER ETAL 3,

SLIDE CONTROL, PARTICULARLY FOR THE ADJUSTMENT OF BODIES OF AXIAL PISTON PUMPS AND/OR MOTORS Filed NOV. 6, 1962 FIG. 3.

INVENTORS ERWIN ALLGAIER KASPAR RITTER ATTORNEY.

United States Patent M 3,175,365 SLIDE CONTROL, PARTICULARLY FOR THE AD- JUSTIVENT 0F SWlNGlNG BODIES OF AXIAL PISTON PUMPS AND/0R MOTORS Erwin Allgaier, Boll, Kreis Goppingen, Wurttemberg,

and Kaspar Ritter, Kirchheim, Tech, Germany, assignore to Kopat Gesellschaft fur Konstrukfion Entwiclrlung und Patentverwertung m.b.H. 8: Co., KG., Goppingen, Wurttemherg, Germany, a corporation of Germany Filed Nov. 6, 1962, Ser. No. 235,700 Claims priority, application Germany, Nov. 9, 1961, K 495,157 2 Claims. (Cl. 60-53) The present invention relates to a slide control, particularly for the adjustment of swinging bodies of axial piston pumps and/or motors, which are mounted for angular adjustment within a rotary housing.

In the known slide controls of this type generally cylindrical coupling pins are provided on the swinging levers, which coupling pins are guided in slots of a width as much as possible exactly adjusted to the diameter of the pins having parallel walls. These slide guides have, however, a number of heavily weighing drawbacks. Thus, it is, for instance, unavoidable, that during a longer operational period, a certain play is developed between the coupling pins and the guide slots due to wear by sliding friction on the highly loaded line contact places, which play interferes with the exactness of the control steps. First of all, the production of the guide slots applying the required exactness, which slots are curved for at least a part of their length, necessitates an appreciable expense in the forming and polishing of the slots.

The present invention constitutes an element of a drive disclosed in US. Patent No. 3,046,744, dated July 31, 1962.

It is, therefore, one object of the present invention to provide a slide control, particularly for the adjustment of swinging bodies of axial piston pumps and/ or motors which are mounted within a rotary housing for angular adjustment, which makes possible an appreciably simplified and thus also faster and more economical production of the guides and simultaneously provides appreciably more favorable operational conditions.

It is another object of the present invention to provide a slide control, particularly for the adjustment of swinging bodies of axial piston pumps and/ or motors, which are mounted within a rotary housing for angular adjustment, wherein the slide guide has a cross-section which is decreasing as to its width in the direction of its depth and in which a coupling member, adjusted in its crosssection. to the slide profile, is disposed on the adjustment lever of the swinging body. Due to the change of the guide slots having parallel side faces the cross-section of which has a width decreasing in the direction of its depth, the possibility is provided to produce in one working step the guide paths by means of a precision-forging process in drop-forgings, whereby the Working time is reduced toa small part of the time period required previously for the production of the guide slots. The exaotness which can be achieved in the forging process is first of all completely suificient, because the cross-section of the guide decreasing in the direction of its depth and the outer shape of the coupling means complementary thereto, permit a play-free adjustment of the slide guides even in case of certain deviations in the Working depth. Simultaneously this cross-sectional shape permits also at any time a later adjustment of the slide guides, if after a longer working period a certain play should appear due to wear.

It is still another object of the present invention to provide a slide control, particularly for the adjustment of 3,175,355 Patented Mar. 30, 1965 swinging bodies of axial piston pumps and/or motors,- Which are mounted within a rotary housing for angular adjustment, wherein the slide guide has a cross-section with a deepened head range and the coupling member consists of a hardened and polished steel ball which is mounted in a ball socket, preferably of bronze, adjustably disposed on the adjusting lever of the swinging body. By this arrangement, conventional steel balls available on the market at particularly reasonable costs, can be used as coupling means, which steel balls can perform in addition, an at least partly rolling movement in the coordin ated slide guide due to their easily rotatable mounting in the adjustable ball sockets made of a material having favorable sliding characteristics. By this arrangement, any danger of local wear of the coupling members is avoided and simultaneously, a particularly soft and friction-poor working of the slide guide is assured.

With these and other objects in View, which will become apparent in the following detailed description, the present invention will be clearly understood in con nection with the accompanying drawing, in which:

FIGURE 1 is an axial section of the hydrostatic torsional moment transformer of which an axial piston pump is shown in full and an axial piston motor is shown in part only, since the axial piston motor is identical with the axial piston pump, the swinging bodies of the axial piston pump and of the axial piston motor being mounted for angular adjustment within a common rotary housing;

FIG. 2 is a section along the lines 2-2 of FIG. 1; and

FIG. 3 is an axial section along the lines 33 of FIG. 1 through a part of the hydromatic torsional moment transformer from which the inner parts have been removed showing the swinging body of the axial piston pump in full lines in the original position and in dotted lines in the displaced positon.

Referring now to the drawing, the hydrostatic drive comprises a swinging body 1 of the axial piston-pump 2, which swinging body 1 is mounted for angular adjustment in a rotary housing 3 for changing the stroke of the pistons 4 about the axis 5. In order to adjust the swinging body 1 to the particularly desired oblique position, adjustment levers 6 and 6 are provided on the swinging body 1, the adjustment levers 6 and 6' having at their ends coupling members 7 and 7 in the shape of steel balls adjustably mounted by means of screwed-in ball sockets 3, 8 of bronze. The coupling members '7 and 7 engage slide guides 9 and 9' having a tapered down. cross-section and having recesses it) and it)" in the head portion. The slide guides 9 and 9' are worked into the particular guide pieces 11 and 11' in a precision forging process, which guide pieces 11 and 11 in turn are secured in a cylindrical control body 12, which is longitudinally movable, yet guided non-rotatably on the rotary housing 3. By displacement of the control body 12 on the rotary housing 3 in one or the other direction of the double arrow 13 over a radial bearing 14, the swinging body 1 can be adjusted about the axis 5 within the rotary housing 3 during operation in one or the other direction of the double arrow 15 (FIG. 3) to a displaced position shown in dotted lines, and, thereby, the stroke of the pistons 4 can be changed. The coupling balls 7 and 7 can be adjusted by threading-out the ball sockets 8 and 8 from the adjustment lever 6 and 6' Without play in their slide guides 9 and 9', respectively. By using the elasticity of the cylindrical control body 12 it is suitably possible to provide a certain pretension. The recesses 14 and 10 on the head portions of the slide guides 9 and 9 prevent the occurrence of undesirably high. radial forces during the transfer of the adjustment forces from the control body 12 onto the adjustment levers 6 and 6', respectively, of the swinging body 1. An axial roller bearing 16 is disposed inside of the swinging body 1 for engagement with the outer ends of the pistons 4 of the axial piston pump 2, which axial roller bearing 16 transmits the very great forces exerted in axial direction of the pistons 4 of the axial piston pump 2 upon the swinging body 1.

A displacement of the cylindrical control body 12 on the rotary housing 3 of the transmission can be brought about, so that the relative angular position of the swinging body 1 is changed and the transmission ratio is changed. In this manner, the transmission ratio can be adjusted between a reduction ratio of one to infinity and the maximum ratio determined by the construction and dimensions of the axial pistons of the pump and motor, and by the relative angular position of the swinging body 1. It will be understood that shifting of the cylindrical control body 12 in one direction will result in rotation of the output shaft in forward direction, and shifting of the cylindrical control body in the other direction to its end position will result in reversing of the direction of rotation of the output shaft.

While we have disclosed one embodiment of the present invention, it is to be understood that this embodiment is given by example only and not in a limiting sense, the scope of the present invention being determined by the objects and the claims.

We claim:

1. A slide control, particularly for the adjustment of swinging bodies of hydrostatic drives of the type including an axial pistompumpand-motor unit, either unit comprising a rotary housing,

swinging bodies mounted in said rotary housing and .angularly adjustable therein,

said swinging bodies having adjustment levers,

coupling members projecting from said adjustment levers of said swinging bodies,

a control body axially movable on said rotary housing and having slots receiving said coupling members, said slots having at each point of their length a cross section diminishing its width with increasing depth,

and

said coupling members being provided on said adjustment levers of said swinging bodies and having a cross-section complementary to that of said slots.

2. The slide control, as set forth in claim 1, wherein said slots decrease as to their width in the direction of the slot depth,

said coupling members comprise hardened and polished steel balls, and

ball socxets are adjustably mounted in said adjustment levers of said swin ing bodies.

References Cited by the Examiner UNITED STATES PATENTS 924,787 6/09 ianney 91-199 2,633,104 3/53 Lauck et al. 91-l99 3,046,744 7/62 Ritter -53 3,663,381 11/62 Budzich 1G3162 3,082,697 3/63 Lucien 103-462 FOREIGN PATENTS 1,185,654 2/59 France.

433,450 8/26 Germany.

JULIUS E. WEST, Primary Examiner. EDGAR W. GEOGHEGAN, Examiner. 

1. A SLIDE CONTROL, PARTICULARLY FOR THE ADJUSTMENT OF SWINGING BODIES OF HYDRROSTATIC DRIVES OF THE TYPE INCLUDING AN AXIAL PISTON-PUMP-AND-MOTOR UNIT, EITHER UNIT COMPRISING A ROTARY HOUSING, SWINGING BODIES MOUNTED IN SAID ROTARY HOUSING AND ANGULARLY ADJUSTABLE THEREIN, SAID SWINGING BODIES HAVING ADJUSTMENT LEVERS, COUPLING MEMBERS PROJECTING FROM SAID ADJUSTMENT LEVERS OF SAID SWINGING BODIES, A CONTROL BODY AXIALLY MOVABLE ON SAID ROTARY HOUSING AND HAVING SLOTS RECEIVING SAID COUPLING MEMBERS, SAID SLOTS HAVING AT EACH POINT OF THEIR LENGTH A CROSS SECTION DIMINISHING ITS WIDTH WITH INCREASING DEPTH, AND SAID COUPLING MEMBERS BEING PROVIDED ON SAID ADJUSTMENT LEVERS OF SAID SWINGING BODIES AND HAVING A CROSS-SECTION COMPLEMENTARY TO THAT OF SAID SLOTS. 